The present invention relates to a flow control nozzle for gravity feed of water to the finned heat exchange tubes of the dry cooling section of a wet/dry cooling tower.
To control or eliminate the formation of fog plume, the cooling tower industry has recently developed various designs of wet/dry cooling towers. These towers include dry air cooled heat exchanger sections and wet evaporative sections, where the water to be cooled is fed downwardly, transversely to the flow of cooling air. The exiting air from the dry and wet sections are mixed and leave the tower through a common exhaust. This serves to reduce the relative humidity of the exhaust air from the wet section and also reduces water evaporation losses. Reference is made to U.S. Patent No. 3,899,553, Patented on Aug. 12, 1975, and assigned to the same assignee as the present invention, for a complete disclosure of a specific wet/dry cooling tower design for which the flow control nozzle of the present invention is adapted for use. The tower includes a wet evaporative cooling section, having a conventional packing area, positioned immediately below a dry section, having a plurality of vertically spaced heat exchange tubes. Water to be cooled flows directly from a water basin through the tubes for preliminary cooling and is then directed over the packing area of the wet section via spray nozzles associated with the lower ends of each tube. The exhaust air from the wet and dry sections is mixed together prior to emission to the atmosphere.
The present invention is directed to a flow control nozzle for controlling the gravity feed of water from the hot water basin to the heat exchange tubes of the dry cooling section. Because of cooling requirements and water loading, the tubes are not designed to run full, rather a thin film of water flows down the inside surface of the tube. The flow control nozzle must allow a relatively small amount of water to flow through the tube, while still allowing a substantial head of water to exist in the hot water basin.